In a process for preparing the molded articles made of resins such as polyurethane and the like, a mold-releasing agent has heretofore been applied on inner walls of a mold prior to a molding in order to facilitate a release of the molded articles from the mold. The commonly used mold-releasing agent is a solvent type agent prepared by blending a wax, a silicone oil or fluorine compounds with an organic solvent.
In the case where the mold-releasing agent which contains the wax is used, (i) it is difficult to prepare the molded articles having smooth finishing surfaces, (ii) the wax adheres and remains on the surfaces of the molded articles because the agent must be applied in large quantities in order to obtain a sufficient releasing effect and (iii) a working hygienical problem arises because a petroleum solvent is used as a base solvent. When the mold-releasing agent which contains the silicone oil is used, the agent causes a trouble that the adhered silicone oil on the surfaces of the molded articles repels a paint during a process of the secondary treatment. Although the mold-releasing agent which contains the fluorine compounds exhibits an excellent releasing property in a small amount and does not cause the working hygienical problem, it has a difficult point that a use of flon group solvents which are the base solvent of said agent will completely be prohibited in the near future from the viewpoint of a global environmental problem wherein the ozonesphere is destroyed by said solvents.
Therefore, the development of an aqueous mold-releasing agent which can be substituted for the aforementioned solvent type agents is demanded. However, in the case where the aqueous mold-releasing agent is employed, there are problems that not only the resin components such as diisocyanate of foam urethane and the like which are materials of the molded articles are reacted with the remaining water in the mold to rough the surfaces of the molded articles but also the mold-releasing property itself is unsatisfactory.
In order to improve these problems, several aqueous mold-releasing agents have already been provided. For example, an aqueous mold-releasing agent containing emulsified wax which cuts off from the remaining water in the mold on the base of a mesomorphism by a nonionic surfactant (Japanese Patent KOKAI No. 22912/1986), a high solid type mold-releasing agent which consists of only mold-releasing ingredients is sprayed by means of an exclusive spray and an aqueous mold-releasing agent which comprises a fluorine-containing phosphate (Japanese Patent Kokoku No. 23270/1978) or a fluorine-containing phosphonate (Japanese Patent Kokoku No. 6329/1988 and ibid. No. 6330/1988 are cited.
However, in the case of the former two mold-releasing agents, the reactivity between water and resin ingredients cannot sufficiently be prevented and said agents are not put to practical use because the mold-releasing properties thereof are inferior and therefore said agents must be used in large quantities in order to obtain the satisfactory mold-releasing effect. In the case where the aqueous mold-releasing agent which comprises the fluorine-containing phosphate is employed, it is difficult to prepare said mold-releasing agent as an aqueous agent because of low solubility of the phosphate in water and the satisfactory mold-releasing effect has not actually been achieved.